Tooling system

ABSTRACT

A tooling system in a press for forming a product from a blank of material disposed between a punch assembly and a die assembly and a method of using the same. The tooling system comprises a knockout and a bushing. The knockout further comprises a shaft having opposed ends, a plate fixed to one opposed end, and a tapered portion. The bushing is supported by one of the punch and die assemblies and defines a lumen configured to slidably receive the shaft for axial movement between an extended position and a retracted position. The lumen has a tapered receiving section at one end thereof configured to mate with the tapered portion of the knockout when the shaft is in the extended position.

DESCRIPTION OF THE INVENTION

1. Field of the Invention

The present invention relates generally to tooling systems, includingthose used for pressware applications and other material formationapplications. More particularly, the present invention relates to atooling system having a die assembly and a punch assembly, wherein atleast one of the die and punch assemblies has a knockout with an angularportion that mates with a corresponding angular portion of a bushing.

2. Background of the Invention

Tooling systems, including die and punch assemblies comprising a dieset, are mounted in presses and are used for manufacturing numerousproducts and components of products. The die and punch assemblies areused to cut, punch holes in, shape, or otherwise form material, such asmetal, cardboard, plastic, or other stock. The die assembly usually isin the lower or bottom position of the press and the punch assembly inthe upper or top position, although the punch assembly may be on thebottom and the die assembly on top. The press, and the die and punchassemblies mounted therein, may be positioned horizontally, vertically,or at an angle. A “blank” of material to be formed, i.e., unshapedmaterial, such as a flat sheet of cardboard or metal, passes between andis clamped by the die and punch and is held in place while the die andpunch come together to form the material. The blanks pass between the“front sides” of the die and the punch assemblies, which are the sidesfacing the blank, as opposed to the “back sides,” which are the sides ofthe die and punch assemblies facing away from the blank. The die andpunch assemblies, or a series of die assemblies and punch assemblies,are activated to form the material into a product or a component of aproduct, such as a metal hub cap for a car, a paper cup or plate (i.e.,pressware formation), or a plastic toy, by example only.

Both the die and the punch assemblies may have knockouts and bushingsfor holding the blank in place, assisting in the forming or shaping thematerial, and for knocking the formed product out of the die set.Knockouts commonly have round shafts or stems and may have hardenedsleeves pressed into the main shaft diameter. The knockout shaft isslidably disposed within the bushing, which has a lumen or bore forreceiving the knockout shaft. A split clamp is clamped around the shaftof the knockout on the back side of the die (the side opposing the frontside that faces the blank), which holds the knockout in positionrelative to the bushing and prevents the knockout from over-extendingand sliding out of the front side of the die upon activation. Theknockout shaft typically has a reduced diameter at the split clamplocation.

In a system having the die assembly as the bottom of the die set, theknockout is activated upwards by pressure (pneumatic, hydraulic, etc.)prior to insertion of the blank, so that the knockout extends upwardstowards the blank on the front side of the die assembly. The knockout isfully extended when the split clamp reaches the bushing on the bottomside of the die assembly. When extended, the knockout supports the blankas it enters the die set and in conjunction with the punch assembly,clamps the blank on-center during the blank draw-in, and maintains theblank on-center as the punch assembly forms the product or component.After product formation, the die knockout is deactivated (i.e., thepressure is released) and the knockout slides away from the product,retracting into the bushing as the die set opens, so that the product isnot damaged. If the product remains in the bottom half of the die set,the knockout may be reactivated to extend out of the die after the dieset has reopened to eject or “knock out” the product and then retract inpreparation for receiving the next blank. The knockout is activatedupwards as the next blank enters the die set for product formation, andthe process described above repeats itself.

The cycling rate of the knockout, meaning the rate at which the knockoutextends and retracts or is activated and deactivated within the dieassembly, varies with the particular tooling application. Typical valuesfor pressware applications (i.e., the formation of paper plates, bowls,cups, etc.) under normal conditions is one cycle of the knockout every1-2 seconds, where numerous cycles, in excess of 20 million, can berealized by the knockouts before replacement. Such cycling rates causewear to the components. Accordingly, both knockouts and bushings usuallyare made of a strong metal, such as steel or iron, to aid inwithstanding the wear. For example, knockouts may be comprised of 1018steel, and bushings may be comprised of stainless steel, although othermaterials may be used.

Notwithstanding the strength of the metals, the die set components tendto wear out quickly, particularly the bushing, which is the main wearcomponent. For example, bushings used for pressware applicationstypically wear out in a matter of three months. Furthermore, knockoutshafts tend to break where the split clamp attaches at the portion ofreduced diameter due to repeated cycling, heat, and/or excessive loads,such as when the activation pressure is set too high. This wear andbreakage results in down time for replacing worn components as well as aloss in product quality as the components wear.

The wear is exacerbated when the press in which the knockout and bushingoperate is positioned at an angle or vertically (i.e., the knockoutmoves horizontally), as opposed to horizontally (i.e., the knockoutmoves vertically). Even with typical knockout-to-bushing clearances,when the die set is positioned at an angle, the knockout can tipslightly in its extended position. Wear of the knockout or the bushingoccurs along a linear portion of the knockout and the bushing due to thefriction along the line of contact between the two components, where thelinear contact is created by the effect of the angle of the press andgravitational forces. Such linear wear causes the knockout to tipfurther off-center, resulting in one side of the knockout being higherthan the other when extended. As the blank is inserted into the die set,the un-centered knockout that should be supporting the blank may insteadtip slightly and prevent the blank from being drawn in or properlyaligning between the die and the punch assemblies. Furthermore, even ifthe blank is properly drawn into the die set, as the knockout retractsduring the material formation process, the blank may be pulled slightlybackwards. Worn knockouts and bushings tend to pull the material evenfurther back, and visibly off-center, which disrupts the formationprocess and can adversely affect the quality of the product formed.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a tooling system in apress for forming a product from a blank of material disposed between apunch assembly and a die assembly and a method of using the same. Thetooling system comprises a knockout and a bushing. The knockout furthercomprises a shaft having opposed ends, a plate fixed to one opposed end,and a tapered portion. The bushing is supported by one of the punch anddie assemblies and defines a lumen configured to slidably receive theshaft for axial movement between an extended position and a retractedposition. The lumen has a tapered receiving section at one end thereofconfigured to mate with the tapered portion of the knockout when theshaft is in the extended position.

The present invention is also directed to a method of operating animproved knockout in a press for forming a product from a blank ofmaterial disposed between a punch assembly and a die assembly. Themethod of operating the improved knockout comprises slidably supportinga shaft having opposed ends in a lumen defined by a bushing configuredin one of the punch and die assemblies; selectively moving the shaftaxially between an extended position and a retracted position;supporting the blank with a plate fixed to a first end of the shaftduring movement of the shaft from the extended position to the retractedposition; knocking out the product from the die assembly during movementof the shaft from the retracted position to the extended position; andsymmetrically engaging a tapered portion fixed to a second end of theshaft with a tapered recess in the bushing when the shaft is in theextended position.

Additional objects and advantages of the invention will be set forth inpart in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention will be realized and attained bymeans of the elements and combinations particularly pointed out in theappended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate the various features and aspectsof the tooling system and its method of use in a tooling procedure, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 illustrates a cross-sectional view of a press including a toolingsystem having a die assembly with a tapered knockout and a bushing and apunch assembly, consistent with the present invention.

FIGS. 2 a-2 c illustrate an exemplary die assembly wherein a taperedknockout is extended, consistent with the present invention. FIGS. 2 aand 2 b are perspective views of the front side and the back side of thedie assembly, respectively, and FIG. 2 c illustrates a cross-sectionalview of the die assembly in the position of FIGS. 2 a and 2 b.

FIGS. 3 a-3 c illustrate an exemplary die assembly wherein a taperedknockout is retracted, consistent with the present invention. FIGS. 3 aand 3 b are perspective views of the front side and the back side of thedie assembly, respectively, and FIG. 3 c illustrates a cross-sectionalview of the die assembly in the position of FIGS. 3 a and 3 b.

FIGS. 4 a and 4 b are cross-sectional and front plan views,respectively, of an exemplary tapered knockout with a square shaft usedin a tooling system, and FIG. 4 c is a section through the piece of thetapered knockout in FIGS. 4 a and 4 b, consistent with the presentinvention.

FIGS. 5 a and 5 b are cross-sectional and front plan views of anexemplary bushing with a square shaft receiver used in a tooling systemfor guiding the tapered knockout in FIG. 4, consistent with the presentinvention.

FIGS. 6 a and 6 b are cross-sectional and front plan views,respectively, of another exemplary tapered knockout with a round shaftused in a tooling system, and FIG. 6 c is a section through the piece ofthe tapered knockout in FIGS. 6 a and 6 b, consistent with the presentinvention.

FIGS. 7 a and 7 b are cross-sectional and front plan views of anotherexemplary bushing with a round shaft receiver used in a tooling systemfor guiding the tapered knockout in FIG. 6, consistent with the presentinvention.

FIGS. 8 a-8 d illustrate perspective views of a portion of exemplarytapered knockouts employed in a tooling system, consistent with thepresent invention. FIG. 8 a illustrates a knockout with a cone-shapedtapered portion; FIG. 8 b illustrates another knockout with acone-shaped tapered portion; FIG. 8 c illustrates a knockout with anobelisk-shaped tapered portion; and FIG. 8 d illustrates a knockout witha pyramid-shaped tapered portion.

FIGS. 9 a-9 d illustrate cross-sectional portions of exemplary toolingsystems consistent with the present invention. FIG. 9 a is a partialcross-section of an embodiment of an unused knockout and bushing of thepresent invention. FIG. 9 b shows the partial cross-section of theknockout and bushing of FIG. 9 a after being operated at an angle, andillustrates wear to the tapered knockout and bushing. FIG. 9 c is apartial cross-section of another embodiment of an unused knockout andbushing of the present invention. FIG. 9 d shows the partialcross-section of the knockout and bushing of FIG. 9 c after beingoperated at an angle, and also illustrates wear to the tapered knockoutand bushing.

FIGS. 10 a and 10 b illustrate cross-sectional portions of an exemplarytooling system consistent with the present invention. FIG. 10 a is apartial cross-section of an embodiment of an unused knockout and bushingof the present invention. FIG. 10 b shows the partial cross-section ofthe knockout and bushing of FIG. 10 a after being operated vertically,and illustrates wear to the tapered knockout and bushing.

DESCRIPTION OF THE PRESENT INVENTION

Reference will now be made in detail to implementations of the toolingsystem as illustrated in the accompanying drawings. Wherever possible,the same reference numbers will be used throughout the drawings to referto the same or like parts.

FIGS. 1-10 illustrate preferred embodiments and components of a toolingsystem, consistent with the present invention. Advantages of the toolingsystem of the present invention are described herein and are illustratedin the accompanying drawings. For example, the tapered knockout does notrequire a split clamp, thus the diameter of the knockout shaft is notreduced to accommodate the split clamp. As a result, shaft breakage thatpresently occurs at the stress point of the reduced diameter after ashort period of use is avoided. Furthermore, the tooling system isself-centering and self-leveling and reduces wear on the bushing andknockout, thereby improving product formation. These advantages willbecome apparent in discussing the structure and operation of the toolingsystem.

Structure of the Tooling System

FIG. 1 illustrates an exemplary press 1 containing tooling system 100,including a die assembly 140 and a punch assembly 130. Press 1 is shownat approximately a 45 degree angle, but press 1 may be situatedhorizontally, vertically, or at any angle between horizontal andvertical. Due to gravity, however, wear on tooling system 100 isincreased when press 1 is situated vertically or at an angle so thatknockout 200 extends and retracts within press 1 horizontally or at anangle.

Tooling system 100 draws in a blank 150 of material to be formed by thepunch assembly 130 and die assembly 140. Blank 150 may be paper,cardboard, metal, plastic, or any other material suitable to be moldedor formed. Blank 150 may be drawn into tooling system 100, dropped intotooling system 100 by gravity, such as when press us positionedhorizontally or at an angle, or otherwise presented to tooling system100. Punch and die assemblies 130, 140 then mold blank 150 into amember, such as a product or component, and tooling assembly 100 kicksor knocks the formed product out in preparation for receiving anotherblank 150, as will later be described with respect to the operation oftooling system 100. It is to be understood that delivery systems thatdeliver the blanks to the tooling system, and removal systems thatremove the molded members after the tooling system knocks them out, arebeyond the scope of the present invention.

Exemplary punch assembly 130 includes a base 121, a bushing 400, and apunch 500. Punch assembly 130 may also include a driving system (e.g.,mechanical cam, pneumatic, hydraulic, not shown) to cause punch 500 toreciprocate within bushing 400. Bushing 400 is mounted to plate 121through a hole 181 in plate 121. Bushing 400 is configured to supportpunch 500 if punch 500 is static, and to guide punch 500 if it isactive, i.e., the driving system causes punch 500 to reciprocate withinbushing 400. Punch 500 includes a punch shaft 504 connected to a punchplate 502. Punch shaft 504 and punch plate 502 may be of any shape,depending on the tooling application. For example, in presswareapplications for paper plate formation, punch plate 502 is round.Bushing 400 has a lumen 402 configured to match the shape of punch shaft504. All components of punch assembly 130 may be made of various rigidand strong materials, including, but not limited to, metals such assteel, ductile iron, or titanium (if weight reduction is a concern).

Die assembly 140 is configured to mate with punch assembly 130 to formproducts, such as paper plates, as shown in FIG. 1. Die assemblyincludes a base 120, a die 170, a die support 255, a tapered knockout200, and a bushing 300, as shown in FIGS. 2 and 3. FIGS. 2 a and 2 bshow perspective views of the front and back sides, respectively, of anembodiment of die assembly 140 of tooling system 100, and FIG. 2 c showsa cross-sectional view, wherein tapered knockout 200 extends out of die170. FIGS. 3 a-3 b show the front and back sides, respectively, of anembodiment of die assembly 140, and FIG. 3 c shows a cross-sectionalview, wherein tapered knockout 200 retracts and is flush with die 170.These components of die assembly 140 may be made of similar rigid andstrong materials as those of punch assembly 130, including but notlimited to metals such as steel, ductile iron, or titanium (if weightreduction is a concern).

Base 120 (FIG. 1) is mounted within press 1 through mount holes 260.Base 120 supports or mounts bushing 300 and die 170, and may be of anysuitable shape. A hole 180 is cut in base 120 for inserting portions ofbushing 300 and knockout 200. Base 120 may have one or more dowel pins122 (FIG. 1) to align bushing 300 and to secure bushing 300 to base 120or may have screws 330 or an alternative attachment mechanism. Base 120(FIG. 2) also has mount holes 262 and 264 (FIGS. 2 b, 3 b) for similarlysecuring die 170 and die ring 255, respectively, to base 120. Vents 268in base 120 allow venting of steam, heat, or air. As shown in FIGS. 2 band 3 b, the back side of base 120 has grooves 275 to accommodate wiresor cables 270 (FIG. 3 a).

Die 170 is mounted to base 120 through mount holes 262 and is thecomponent of die assembly 140 that works in conjunction with punch plate502 to form a member. In the embodiment of die assembly 140 shown inFIGS. 2-3, die 170 is round and has a rim portion 252 and a grooveportion 250 suitable for forming paper plates. However, die 170 may beof any size or shape or configuration suited to the particular toolingapplication in which it is used. Die base 120 also has a hole 272through which tapered knockout 200 is operable to project, where hole272 is configured to match the size and shape of knockout plate 206.

Die support 155 is mounted on base 120 and surrounds die 170. Diesupport 255 has a lumen (not shown) configured to accommodate die 170.Once die 170 is disposed in the lumen of support 255 and they aremounted on base 120, a gap 165 is formed between die support 255 and die170.

Tapered knockout 200, shown in more detail in FIGS. 4 and 6, is disposedin bushing 300. Tapered knockout 200 includes a tapered portion 210formed or attached to the end of a shaft 204, 205 and a knockout plate206 attached to the opposite end of shaft 204, 205. Tapered portion 210also has a hole 202 extending into shaft 204, 205 for insertion of aknockout rod for activating tapered knockout 200 in conjunction with thedrive system (not shown), the activation of which is known in the artand is beyond the scope of this invention.

FIGS. 4 a and 6 a illustrate cross-sectional views of tapered knockout200 having square shaft 204 and round shaft 205, respectively,consistent with the present invention. Notably, however, shaft 204, 205may be any symmetrical shape, such as a triangle-shaped shaft 211 (FIG.8 d). Aside from the shape of shaft 204, 205, the knockouts illustratedin FIGS. 4 a-4 c (square) and 6 a-6 c (round) are otherwise structurallythe same. The difference between shafts 204 and 205 will be discussed inrelation to the operation of tooling system 100. Shaft 204, 205 may beof any size (in terms of width for a square shaft or diameter for around shaft) and length. The width and length is dependent upon, amongother things, the tooling application, the depth of the product beingformed, the forming base material, the size of knockout plate 206 thatshaft 204, 205 supports, the draw-in location for blank 150 supported byknockout plate 206, and the length of bushing 300 that guides shaft 204,205. The width or diameter of shaft 204, 205 is generally uniform, andthere is no portion at which the width or diameter of shaft 204, 205 issignificantly reduced.

Tapered portion 202 is configured as a symmetrical taper-shape and iscoupled to or molded on the end of shaft 204, 205, 211. Exemplary shapesof tapered portion 202 are illustrated in FIGS. 8 a through 8 d,including conical 202 (FIG. 8 a), conical 202 with a step 207 (FIG. 8b), obelisk 201 (FIG. 8 c), and pyramid 203 (FIG. 8 d). Any symmetricalshape having a portion that tapers directly into the shaft (FIGS. 8 a, 8c, 8 d), or tapers towards and forms step 207 with the shaft (FIG. 8 b),and is centered with respect to the shaft, is adequate for the presentinvention. Moreover, tapered portion 201, 202, 203 is in no way limitedto the shapes depicted in FIGS. 8 a-8 d. Similarly, the shaft may beround 204 (FIGS. 8 a, 8 b), square 205 (FIG. 8 c) or triangular 211(FIG. 8 d), or any other symmetrical shape that is centered with respectto tapered portions 201, 202, and 203.

The angle (denoted as “x”) of the tapered portion 202 illustrated inFIGS. 4 a and 6 a is approximately 15 degrees with a preferred range ofbetween 5 degrees and 45 degrees, although angles as small as 5 degreesand as large as 85 degrees are consistent with the present invention.The size (i.e., the smallest area or diameter of tapered portion 202along a length) of tapered portion 202 may be the same as the size(i.e., width or diameter) of shaft 204, 205 to which it attaches or isformed. Alternatively, as shown in FIGS. 2 c, 3 c, 8 b, 9 c, and 9 d,the smallest area or diameter of tapered portion 202 along a length oftapered portion 202 may be larger than the size, (i.e., width ordiameter) of shaft 204, 205 to which it attaches or is formed, such thatthe top of tapered portion 202 forms step 207 with shaft 204, 205. Thelength of tapered portion 202 varies, depending on, among other factors,the tooling application, the length of shaft 204, 205, andcharacteristics of bushing 300 that guides shaft 204, 205 and mates withtapered portion 202. There is no limitation or preferred range for thelength or size of tapered portion 202, the ratio of the shaft length tothe taper length, or other such measurements.

Knockout plate 206, which is attached to the opposite end of shaft 204,205 from tapered portion 202, is shown in detail from the front in FIGS.4 b and 6 b. The size (i.e., diameter or width) and shape of knockoutplate 206 varies with the tooling application, and is illustrated as adisk for pressware applications as an example only. Knockout plate 206may include cutouts 208, which are recessed areas that are cut out ofknockout plate 206 for weight reduction purposes. By decreasing theweight of knockout plate 206, the stress and wear on tooling system 100is also reduced. Although cutouts 208 are circular in the illustration,they may be of any shape, or in the form of a groove or other cutout,such that the weight of knockout plate 206 remains evenly distributedand centered. Knockout plate 206 also includes grooves 212 along itssides. Grooves 212 permit heat, air, and/or steam to vent. Grooves 212are optional and exemplary only, and may be replaced by holes drilled inknockout plate 206, or some other venting mechanism.

Bushing 300, which guides tapered knockout 200, is illustrated in moredetail in FIGS. 5 and 7. Bushing 300, which is separable into twosymmetrical sections, a first bushing section 350 and a second bushingsection 360, is mounted to base 120 by attachment plate 304 to define alumen 315 having a shaft receiver 320, 321 and a tapered receivingsection or tapered receiver 310.

First and second bushing sections 350 and 360 form bushing 300 when eachsection 350, 360 is fitted into die base hole 180 and is attached to diebase 120 around tapered knockout 200, as shown in FIGS. 1-3. Eachsection 350, 360 has a half of attachment plate 304 and is configuredwith a half of tapered receiver 310 and shaft receiver 320, as shown inFIGS. 5 and 7. When attachment plate 304 for each bushing section 350,360 is attached to die base 120, gaps 314 are formed between bushingsections 350 and 360. Bushing 300 is formed as two separate sections inorder to dispose tapered knockout 200 in bushing 300, as will bedescribed with respect to the installation of tooling system 100 in theoperation section.

Attachment plate 304 is configured to secure bushing 300 (i.e., bushingsections 350, 360) to the bottom of base 120 (illustrated in FIGS. 1, 2b, and 3 b). However, attachment plate 304 could also be secured to thefront side of base 120. As shown in FIG. 1, attachment plate 304 may bealigned on dowel pins 122 via attachment holes 306 (shown in FIGS. 2 and3), and may be secured to base 120 with screws 330 or a similarattachment device through attachment holes 306. Alternatively, bushing300 may be otherwise secured to base 120, as long as bushing 300 isreplaceable once worn. Attachment plate 304 also may have vents 308 toallow air, heat, and steam to escape. Attachment plate 304 and vents 308are disk-shaped in FIGS. 5 b and 7 b, but may be any shape.

Attachment plate 304 also defines a back side 304 of bushing 300 thatextends out of hole 180 from the bottom side of base 120 (FIGS. 1, 2 b,3 b), and a front side 316 that extends into hole 180 (FIG. 1). Whentapered knockout 200 is fully retracted, the bottom of knockout plate206 rests on front side 316 of bushing 300 and the top of knockout plate206 is flush with the bottom of groove 251 of die 170, as shown in FIGS.3 a and 3 c.

Tapered receiver 310, which is a tapered recess, is configured to matewith tapered portion 202, as shown in FIGS. 1, 9 a-9 d, and 10 a-10 b.The characteristics of tapered receiver 310, such as angle (labeled “y”in FIGS. 5 a and 7 a) and length, therefore are similar to those oftapered portion 202 (such as angle x, length). If tapered portion 202forms step 207 in meeting with shaft 204, 205 as previously described,tapered receiver 310 also forms a step 307 in meeting with shaftreceiver 320, as shown in FIGS. 2 c and 9 c.

As shown in FIGS. 9 a-9 d, a gap 309 is created at the juncture of thetop of tapered portion 202 and the top of tapered receiver 310. For theembodiment in which tapered portion 202 tapers into shaft 204, as shownin FIGS. 9 a-9 b, the length of tapered receiver 310 (designated “↓₂”)is slightly shorter than the length of tapered portion 202 (designated“↓₁”). For the embodiment in FIGS. 9 c-9 d in which step 207 is formed,the length of the length ↓₂ of tapered receiver 310 is longer than thelength ↓₁ of tapered portion 202. The purpose of these lengthdifferences will be described with respect to the operation of toolingsystem 100.

Shaft receiver 320, 321, adjacent to tapered receiver 310, is a lumen orbore configured to match the size and shape of shaft 204, 205 of taperedknockout 200, as illustrated in FIGS. 2 c, 3 c, 5, and 7. In FIGS. 5 aand 5 b, shaft receiver 320 is square to correspond to square shaft 204in FIGS. 4 a-4 c. Another exemplary bushing 300 with a round shaftreceiver 321 is illustrated in FIGS. 7 a and 7 b, which corresponds withshaft 205 in FIGS. 6 a-6 c. Although these illustrations depict shaftreceiver 320, 321 as square or round, shaft receiver 320, 321 isconfigured to match the shape of shaft 204, 205, which may be of anysymmetrical shape. Aside from the shape of shaft receiver 320, 321,bushings 300 illustrated in FIGS. 5 a-5 b (square) and 7 a-7 b (round)are otherwise similar structurally. The difference between shaftreceivers 320, 321 will be discussed in relation to the operation oftooling system 100. Regardless of the shape of shaft receiver 320, 321,it must be slightly larger than the width or diameter of the shaftdisposed therein to permit the shaft to slide within it, and preferablyis 0.004 to 0.007 inches larger than shaft 204, 205 before use has wornthe components and increased the tolerance.

Operation of Tooling System

Generally speaking and as shown in FIG. 1, after tooling system 100 isinstalled in press 1, tapered knockout 200 and punch 130 are activatedto form products or components from blanks 150. Installation of toolingsystem 100 occurs each time a component is worn and needs to bereplaced. Given the reduced wear and the reduced effect of wear oftooling system 100, which will be discussed with respect to FIGS. 9 and10, installation procedures do not have to be conducted as often in thepresent system.

FIGS. 1-3 serve to illustrate the installation of some of the componentsof tooling system 100. By example only, the installation of variouscomponents in die assembly 140 will be explained. To install toolingsystem 100 in press 1, die support 255 is mounted on base 120 and die170 is inserted in die support 255 and secured to the front side of base120. Tapered knockout 200 is inserted into hole 272 of die 170 and hole180 from the front side of base 120, tapered portion-end first, so thatshaft 204 projects through to the backside of die plate 120. Bushingsections 350, 360 are then placed around the projecting section of shaft204 of tapered knockout 200 and bushing front side 316 is inserted ontodowel pin 122 from the backside of base 120, so that shaft receiver 320surrounds shaft 204 on the back side of base 120. Attachment holes 306of attachment plate 304 are then aligned with dowel pins 122 of base120, and attachment plate 304 is secured to base 120 by inserting screws330 into attachment holes 306 or by dowel pins 122. Alternativeattachment mechanisms may also be used. Tapered knockout 200 is thenconnected to the driving system by a knockout rod to hole 210 in taperedportion 202. The driving system and its connection to tooling system100, which is beyond the scope of the present invention, is configuredto activate the knockout. Notably, any mechanism known in the toolingarts to activate the knockout may be used with the present invention. Atthis point, die assembly 140 and punch assembly 130 are installed andtooling system 100 is ready to operate.

In operation, tapered knockout 200 initially is in the retractedposition, shown in FIG. 3. For example, in pressware applications, thetop of knockout plate 206 is flush with the bottom of groove 251 of die170 and the bottom of knockout plate 206 rests on bushing front side 316when tapered knockout is fully retracted (FIG. 3 a). Meanwhile, taperedportion 202 projects out of bushing back side 302, as shown in FIG. 3 b.

When press 1 is activated, blank 150 is gravitationally or otherwisedrawn into die set 160 between the front sides of die assembly 140 andpunch assembly 130 in preparation for product formation (FIG. 1). Blank150 is gripped between die assembly 140 and punch assembly 130 so thatblank 150 remains centered and level. More specifically, uponactivation, tapered knockout 200 moves upward, so that knockout plate206 moves upward to support incoming blank 150 and prevents blank 150from diving into cavity 151. Shaft receiver 320 of bushing 300 guidesshaft 204 as it is activated upward by the driving system.Simultaneously, punch 500 moves downward, so that blank 150 is grippedbetween and held on center by punch 500 and knockout 200.

Eventually, tapered knockout 200 is fully extended and stops movingupward, as shown in FIG. 2. At this point, the bottom of tapered portion202 is flush with the bottom of back side 302 of bushing 300 (FIG. 2 b),tapered portion 202 mates with tapered receiver 310 (FIG. 2 c), andknockout plate 206 projects out of hole 272 of die 170 (FIGS. 2 a, 2 c)and is level with incoming blank 150 (FIG. 1).

Tapered knockout 200 is then deactivated and retracts to its initialposition described above as punch 130 activates to extend punch plate502 downward to mate with die 170 and mold blank 150 into a member.

Many tooling applications require the knockout to then reactivate beforeanother blank 150 is inserted into tooling system 100 in order to “knockout” the formed member from die assembly 170. Tapered knockout 200 isactivated again, in the manner described above, and again fully extendsout of die 170 to knock the product out of tooling system 100 inpreparation for receiving another blank 150 and performing anothercycle.

Referencing FIGS. 1, 2 and 3, a pressware application serves toillustrate the operation of tooling system 100. Tooling system 100 isactivated so that tapered knockout 200 extends upward out of die 170until fully extended. Cardboard blank 150 is drawn in and rests onknockout plate 206. Knockout plate 206 then retracts until it is flushwith die 170 as punch plate 502 extends and mates with die 170 to formblank 150 into a paper plate with a rim. Once the plate is formed,tapered knockout again extends upward to knock the paper plate out oftooling system 100 in preparation for receiving another cardboard blank150.

Operating tooling system 100 creates friction between the contact pointsof tapered knockout 200 and bushing 300, which causes wear to thecomponents over numerous cycles. Although bushing 300 and taperedknockout 200 do indeed wear with use, the structure of tooling system100 reduces wear and the effect of wear on product formation. Taperedportion 202 replaces the function of the split clamp used in currentsystems, which requires a reduced shaft diameter and leads to shaftbreakage at the reduced diameter. The structure of tooling system 100,including tapered portion 202 and tapered receiver 310, also ensuresthat tooling system 100 is self-centering and self-leveling whenextended, even as it wears, thereby improving product formation.

The structure of tooling system 100 prevents tapered knockout 200 fromsliding out of die assembly 140 without requiring a reduced diameter orsize of shaft 204, thereby avoiding shaft breakage at the reductionpoints. Shaft 204 is generally of uniform width or diameter, while thediameter of tapered portion 202 is larger than the width or diameter ofshaft 204. The diameter of tapered receiver 310 is larger than the widthor diameter of shaft receiver 320, so that tapered portion 202 mateswith and stops at tapered receiver 310 when tapered knockout 200 isfully extended. Moreover, as previously discussed with respect to FIGS.9 a-9 d, the length of tapered receiver 310 differs from that of taperedportion 202 so that a gap 309 is formed at the junction of the top oftapered portion 202 with tapered receiver 310. Thus, when knockout 200is fully extended, the top of tapered portion 202 does not come intocontact with tapered receiver 310.

Although the shaft may be of any shape, as previously described, shaftshapes that increase the surface area of contact between the shaft andthe shaft receiver tend to create a less detrimental effect on productformation quality as they wear. The greatest wear occurs duringextension and retraction of tapered knockout 200 along the line ofcontact between the shaft surface of the knockout and the shaft receiversurface of the bushing. When operated in an angled press 1 (FIG. 1),the. contact between round shaft 205 (FIG. 5) and shaft receiver 321(FIG. 7) is linear, and the components wear more quickly. In contrast,the contact between square shaft 204 (FIG. 4) and square shaft receiver320 (FIG. 6) is along the flat surfaces of one side of shaft 204 andshaft receiver 320, which does not wear the components as quicklybecause the load is distributed more evenly. Although square shaft 204is therefore preferable to shafts of some other shapes, such as roundshaft 205, shafts of any shape may be used in tooling system 100 becausetapered portion 202 provides tooling system 100 with self-leveling andself-centering characteristics in spite of the wear on tapered knockout200 and bushing 300, as will be discussed.

FIGS. 9 a-9 d and 10 a-10 b illustrate that knockout plate 206 remainslevel and centered because of the structure of tooling system 100,despite wear on knockout shaft 204 and shaft receiver 320. FIG. 9 aillustrates a partial cross-section of an embodiment of tooling system100 when new, and FIG. 9 b illustrates the same cross-section aftertooling system 100 has been operated in angled press 1 (shown in FIG.1). Tapered portion 202 mates with tapered receiver 310 when taperedknockout 200 is fully extended out of die 170, creating gap 309 at thetop of the juncture due to the fact that the length ↓₁ of taperedportion 202 is longer than that of tapered receiver 310 (↓₂). Similarly,FIG. 9 c illustrates a partial cross-section of another embodiment oftooling system 100 when new, and FIG. 9 d illustrates the samecross-section after tooling system 100 has been operated in angled press1 (shown in FIG. 1). Tapered portion 202, having step 207, mates withtapered receiver 310, having step 307, when tapered knockout 200 isfully extended out of die 170. Gap 309 is created at the top of thejuncture due to the fact that the length ↓₂ of tapered receiver 310 islonger than that of tapered portion 202 (↓₁). The surface areas ofknockout shaft 204 and shaft receiver 320 in contact in FIGS. 9 a-9 dtend to be located on one side when tooling system 100 is operated inangled press 1 (FIG. 1).

FIGS. 10 a and 10 b illustrate wear (“w”) that occurs from operation ina press in which tooling system 100 is positioned vertically. FIG. 10 aillustrates a partial cross-section of tooling system 100 when new, andFIG. 10 b illustrates the same cross-section of tooling system 100 afterbeing operated vertically in a horizontal press (instead of at an angle,as shown in FIGS. 9 b and 9 d). Wear (“w”) of knockout shaft 204 andshaft receiver 320 caused by the contact of the two surfaces as knockout200 is extended and retracted vertically in bushing 300 occurs aroundthe entire surface of knockout shaft 204 and shaft receiver 320, and isnot limited to one linear portion or one side.

Despite the wear (“w”) shown in FIGS. 9 b, 9 d, and 10 b, tooling system100 maintains knockout plate 206 in a centered and level position whenextended. Because of the mated, tapered structure of tooling system 100,when knockout 200 is fully extended, tapered receiver 310 mates withtapered portion 202 and maintains knockout plate 206 level and centeredeven if shaft 204 and shaft receiver 320 are worn. Similarly, whenknockout 200 is fully retracted so that shaft 204 retracts into shaftreceiver 320 and knockout plate 206 rests in die 170 (FIG. 3 c),knockout 200 again is centered. Therefore, during blank insertion(knockout fully extended), product formation (knockout fully retracted),and product knockout (knockout fully extended), knockout plate 206 iscentered and level despite wear on the shaft 204 and shaft receiver 320components of knockout 200 and bushing 300.

Additionally, a cushion of air is trapped between the surface of taperedportion 202 and the surface of tapered receiver 310 in gap 309, whichreduces the wear on the components. In traditional tooling systems withsplit collars, the surface area between the rim of the split collar andthe back side of the bushing is small, thus little air is trapped andthe components tend to make a loud sound as they come together when theknockout fully extends. In contrast, tapered knockout 200 makes lessnoise when tapered portion 202 mates with tapered receiver 310 due togap 309 and the increased surface area between the two components,resulting in an increase in the air that is trapped and the cushion thatis created.

Although tooling system 100 of the present invention is primarily shownand described herein with respect to a die assembly on the bottom of adie set comprising die (bottom) and punch (top) assemblies, asillustrated in FIG. 1, tooling system 100 may comprise die and/or punchassemblies wherein the punch assembly is on the bottom and the dieassembly is on the top (not shown). It will be obvious to one skilled inthe field that tooling system 100 may be configured in either the dieassembly or the punch assembly, each of which may be located in eitherthe bottom or the top of the host press. Other embodiments of theinvention will be apparent to those skilled in the art fromconsideration of the specification and practice of the inventiondisclosed herein. It is intended that the specification and examples beconsidered as exemplary only, with a true scope and spirit of theinvention being indicated by the following claims.

1. In a press for forming a product from a blank of material disposedbetween a punch assembly and a die assembly, an improved knockoutcomprising: a shaft having opposed ends slidably supported in one of thepunch and die assemblies for selective axial movement between anextended position and a retracted position; a plate fixed to a first endof the shaft and disposed to support the blank during movement of theshaft from extended to retracted positions and to knock the product outof the one of the punch and die assemblies during movement of the shaftfrom retracted to extended positions; and a tapered portion fixed to asecond end of the shaft and disposed in the extended position tosymmetrically engage a tapered recess in the one of the punch and dieassemblies that slidably supports the shaft.
 2. The press of claim 1,wherein the one of the punch and die assemblies supporting the shaftcomprises a bushing defining a lumen for slidably receiving the shaftand having the tapered recess at one end thereof.
 3. The press of claim1, wherein the shaft is square.
 4. The press of claim 3, wherein the oneof the punch and die assemblies supporting the shaft comprises a bushingdefining a square lumen having the tapered recess in one end thereof. 5.The press of claim 1, wherein the shaft is round.
 6. The press of claim5, wherein the one of the punch and die assemblies supporting the shaftcomprises a bushing defining a round lumen having the tapered recess inone end thereof.
 7. The press of claim 1, wherein the shaft istriangular.
 8. The press of claim 7, wherein the one of the punch anddie assemblies supporting the shaft comprises a bushing defining atriangular lumen having the tapered recess in one end thereof.
 9. Thepress of claim 1, wherein the tapered portion and the tapered recesshave complimentary cone-shapes.
 10. The press of claim 1, wherein thetapered portion and the tapered recess have complimentaryobelisk-shapes.
 11. The press of claim 1, wherein the tapered portionand the tapered recess have complimentary pyramid-shapes.
 12. A toolingsystem in a press for forming a product from a blank of materialdisposed between a punch assembly and a die assembly, comprising: aknockout further comprising a shaft having opposed ends, a plate fixedto one opposed end, and a tapered portion; and a bushing supported byone of the punch and die assemblies and defining a lumen configured toslidably receive the shaft for axial movement between an extendedposition and a retracted position, the lumen having a tapered receivingsection at one end thereof configured to mate with the tapered portionof the knockout when the shaft is in the extended position.
 13. Thetooling system of claim 12, wherein the shaft is square.
 14. The toolingsystem of claim 13, wherein the bushing further defines a square lumen.15. The tooling system of claim 12, wherein the shaft is round.
 16. Thetooling system of claim 15, wherein the bushing further defines a roundlumen.
 17. The tooling system of claim 12, wherein the shaft istriangular.
 18. The tooling system of claim 17, wherein the bushingfurther defines a triangular lumen.
 19. The tooling system of claim 12,wherein the tapered portion and the tapered receiving section havecomplimentary cone-shapes.
 20. The tooling system of claim 12, whereinthe tapered portion and the tapered receiving section have complimentaryobelisk-shapes.
 21. The tooling system of claim 12, wherein the taperedportion and the tapered receiving section have complimentarypyramid-shapes.
 22. A die assembly in a press for forming a product froma blank of material, comprising: a knockout further comprising anelongated shaft having opposed ends, a plate fixed to one end and atapered portion fixed to the other end; and a bushing supported by thedie assembly and defining a lumen configured to slidably receive theshaft for axial movement between an extended position and a retractedposition, the lumen having a tapered receiving section at one endthereof configured to mate with the tapered portion of the knockout whenthe shaft is in the extended position.
 23. A punch assembly in a pressfor forming a product from a blank of material, comprising: a knockoutfurther comprising an elongated shaft having opposed ends, a plate fixedto one end and a tapered portion fixed to the other end; and a bushingsupported by the punch assembly and defining a lumen configured toslidably receive the shaft for axial movement between an extendedposition and a retracted position, the lumen having a tapered receivingsection at one end thereof configured to mate with the tapered portionof the knockout when the shaft is in the extended position.
 24. Atooling system comprising: a punch assembly having a first plate; and adie assembly having a second plate opposing the first plate, wherein atleast one of the punch assembly and the die assembly further comprises:a knockout having an elongated shaft with opposing ends, one of thefirst plate and the second plate fixed to one end of the shaft, and atapered portion fixed to the other end of the shaft; and a bushingdefining a lumen configured to slidably receive the shaft, the lumenhaving a tapered receiving section configured to mate with the taperedportion of the knockout.
 25. The tooling system of claim 24, wherein thedie assembly and the punch assembly are disposed in a press for forminga product from a blank of material disposed between the punch and dieassemblies.
 26. The tooling system of claim 24, wherein the taperedportion of the knockout mates with the tapered receiving section of thelumen when the shaft is in a fully extended position.
 27. A knockout fora press having a punch assembly and a die assembly disposed in opposedselective mating relation for forming a product from a blank, the dieassembly including a plate for receiving the blank and ejecting theproduct, the knockout comprising: a shaft having opposed first andsecond ends, the first end being adapted to carry the plate of the dieassembly; and a tapered portion fixed to the second end of the shaft anddisposed for mating in a complementary recess in the die assembly whenthe shaft is moved to eject the product.
 28. The knockout of claim 27,wherein the shaft is square.
 29. The knockout of claim 27, wherein theshaft is round.
 30. The knockout of claim 27, wherein the shaft istriangular.
 31. The knockout of claim 27, wherein the tapered portion iscone-shaped.
 32. The knockout of claim 27, wherein the tapered portionis obelisk-shaped.
 33. The knockout of claim 27, wherein the taperedportion is pyramid-shaped.
 34. The press of claim 1, wherein an angle ofthe tapered portion is between 5 degrees to 45 degrees relative to anaxis of the shaft.
 35. The press of claim 34, wherein the angle of thetapered portion is approximately 15 degrees.
 36. The press of claim 1,wherein a length of the tapered portion is longer than a length of thetapered recess.
 37. The press of claim 1, wherein a length of thetapered recess is longer than a length of the tapered portion.
 38. Thetooling system of claim 12, wherein an angle of the tapered portion isbetween 5 degrees to 45 degrees relative to an axis of the shaft. 39.The tooling system of claim 38, wherein the angle of the tapered portionis approximately 15 degrees.
 40. The tooling system of claim 12, whereina length of the tapered portion is longer than a length of the taperedreceiving section.
 41. The tooling system of claim 12, wherein a lengthof the tapered receiving section is longer than a length of the taperedportion.